[PATCH 4.9 34/66] ipv6: Fix getsockopt() for sockets with default IPV6_AUTOFLOWLABEL

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>


[ Upstream commit e9191ffb65d8e159680ce0ad2224e1acbde6985c ]

Commit 513674b5a2c9 ("net: reevalulate autoflowlabel setting after
sysctl setting") removed the initialisation of
ipv6_pinfo::autoflowlabel and added a second flag to indicate
whether this field or the net namespace default should be used.

The getsockopt() handling for this case was not updated, so it
currently returns 0 for all sockets for which IPV6_AUTOFLOWLABEL is
not explicitly enabled.  Fix it to return the effective value, whether
that has been set at the socket or net namespace level.

Fixes: 513674b5a2c9 ("net: reevalulate autoflowlabel setting after sysctl ...")
Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 include/net/ipv6.h       |    1 +
 net/ipv6/ip6_output.c    |    2 +-
 net/ipv6/ipv6_sockglue.c |    2 +-
 3 files changed, 3 insertions(+), 2 deletions(-)

--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -290,6 +290,7 @@ int ipv6_flowlabel_opt_get(struct sock *
 			   int flags);
 int ip6_flowlabel_init(void);
 void ip6_flowlabel_cleanup(void);
+bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np);
 
 static inline void fl6_sock_release(struct ip6_flowlabel *fl)
 {
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -156,7 +156,7 @@ int ip6_output(struct net *net, struct s
 			    !(IP6CB(skb)->flags & IP6SKB_REROUTED));
 }
 
-static bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np)
+bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np)
 {
 	if (!np->autoflowlabel_set)
 		return ip6_default_np_autolabel(net);
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -1316,7 +1316,7 @@ static int do_ipv6_getsockopt(struct soc
 		break;
 
 	case IPV6_AUTOFLOWLABEL:
-		val = np->autoflowlabel;
+		val = ip6_autoflowlabel(sock_net(sk), np);
 		break;
 
 	default: